feat: add new rule react/jsx-key

[l2ysho]

Turn on rule to detect missing key prop in JSX.

• main reason is ensure valid react syntax.
• one downside can be a need to refactor old projects.
• feel free to discuss or suggest reviewers

Examples of incorrect code for this rule:

[<Hello />, <Hello />, <Hello />];

data.map(x => <Hello>{x}</Hello>);

<Hello {...{ key: id, id, caption }} />

In the last example the key is being spread, which is currently possible, but discouraged in favor of the statically provided key.

Examples of correct code for this rule:

[<Hello key="first" />, <Hello key="second" />, <Hello key="third" />];

data.map((x) => <Hello key={x.id}>{x}</Hello>);

<Hello key={id} {...{ id, caption }} />

more info about jsx/key-prop